A&P2 CH. 20 PT.2

record of electrical activity of the heart in the myocardium

electrocardiogram

ECG name

electrocardiogram

what is this

?

what is this

?

what is this

?

what is this

?

what is this

?

what does the p wave show?

depolarization of the atria

what does the qrs complex show

ventricular depolarization and atrial repolarization

how long is the qrs complex

0.11 seconds

what does the t wave show

ventricular repolarization

how long is the pr interval?

0.16 seconds

how long is the qt interval

0.36 seconds

what 2 things happen during the pq interval?

1) atria contract and then begin to relax
2) ventricles begin to contract

what happens during the qt interval?

ventricles contract and begin to relax

what is this

?

what is this

?

what is this

?

what is this

?

what is this

?

what are the two parts of the cardiac cycle

1) systole
2) diastole

what is the hearts contracting faze

systole

what is the hearts dilating faze

diastole

what are the 2 periods of systole

1) period of isovolumetric contraction
2) period of ejection

what are the 3 periods of diasole

1) period of isovolumetric relaxation
2) passive ventricular filling
3) active ventricular filling

blood flows from _______ to _______ pressure

higher;lower

contraction ________ pressure

increases

av valve is closed when ventricle pressure is _______ than atrial pressure

greater

pulmonary and aortic semilunar valves are closed when semilunar pressure is ___________ than ventricle pressure

greater

volume of blood in ventricles at end of diastole

end diastolic volume

what is the amount of blood left at end diastolic volume

120-130 ml

what are the two pressures of the ventricles during period of ejection

left ventricle= 120 mmhg
right ventricle= 25 mmhg

what is the end systolic volume

50-60 ml

amount of blood remaining in a ventricle after contraction

end systolic volume

passive ventricular filling accounts for ____% of ventricular filling

70

During isovolumetric contraction, the pressure in the ventricles is _________ than the pressure in pulmonary trunk/aorta pressure

lower

when does the first heart sound occur?

during the phase of isovolumetric contraction

what causes the first heart sound

closure of AV valves

when does the second heart sound occur

ventricular diastole

what causes the second heart sound

closure of semilunar valves

when does the third heart sound occur

early diastole

what causes the third heart sound

Turbulent blood flow into ventricles

what does MAP stand for

mean arterial pressure

MAP equation

MAP= CO x PR

what does CO stand for

cardiac output

what does PR stand for

peripheral resistance

what is PR

total resistance against which blood must be pumped

what is CO

the amount of blood pumped by heart per minute

what is SV

blood pumped during each heart beat

what is HR

number of times heart beats per minute

CO equation

CO = HR x SV

What is the cardiac reserve

difference between resting and maximal CO

what is the hearts intrinsic regulation

normal functional characteristics of the heart that regulate it

what is the preload

the degree of stretch on the heart before it contracts

what effects preload

venous return and end systolic pressure

what is venous return

amount of blood returning to the heart from systolic circulation

what is afterload

pressure the contracting ventricles must produce to overcome the pressure in the aorta and move blood into the aorta

what are the two stimulators of parasympathetic extrinsic regulation

1) vagus nerve
2) actylecholine

what does the vagus nerve do?

decreased the rate of the SA node and slows impulse conduction of the AV node

what does acetylcholine do to the heart

decreases SV and HR by binding to membrane to make more permeable to potassium therefore hyperpolarizing the heart

what are the two stimulators of sympathetic division of extrinsic regulation

1) cardiac nerves
2) epinephrine and norepinephrine

what does the cardiac nerves do to herat

increases heart rate and force of contraction

higher heart beat = _______ cardiac output

higher

where does epinephrine and norpinephrine come from

adrenal medulla

what senses the change in blood pressure

baroreceptors

where is baroreceptors located

in walls of internal carotids and aorta

Where does the baroreceptor signal change in?

parasympathetic and sympathetic divisions

what senses change in ph, co2 and o2

chemoreceptors

where is chemoreceptors located

medulla oblongata

where does chemoreceptors measure o2

aorta and internal carotids

if blood PH increases, the sa node and cardiac muscle would ________ activity

decrease

if blood ph decreases, the sa node and cardiac muscle would _________ activity

increase

Increase in Extracellular Potassium (K+)

Causes a Depolarization (more positive) increases heart rate

decrease extracellular K+

hyperpolarization-- decreases heart rate

increase in calcium would

reduce heart rate

increase in body temperature would ________ HR

increase

decrease in body temp would ________ HR

decrease

what is the baroreceptor reflex

Autonomic response to changes in blood pressure detected by baroreceptors in the carotid artery and aortic arch. Increases in blood pressure activate the baroreceptors which result in inhibition of sympathetic input to the heart and vasculature and activation of vagal input to the heart resulting in decreased blood pressure. Decreases in blood pressure result in activation of sympathetic input to the heart and vasculature and inhibition of vagal input to the heart.

what is the chemoreceptor reflex

chemoreceptors monitor chemical composition of blood

increased sympathetic impulses increase BP to drive gas exchange through the lungs

what are the two places chemoreceptors are

1) medulla oblongata
2) carotid body

what are the two places baroreceptors are

1) internal wall of carotid artery
2) aorta

what nerve does the parasympathetic nerve fibers effect

vagus nerves

what nerves does the sympathetic nerve fibers effect

cardiac nerves

what gland does the sympathetic nerve fibers effect

adrenal gland

where is epinephrine and norepinephrine produced

adrenal medulla

what is endocarditis

inflammation of the endocardium

what is myocarditis

inflammation of the myocardium

what is pericarditis

Inflammation of the pericardium which is usually idiopathic or viral (90%). Other causes include bacterial, autoimmune, connective tissue disease, neoplasm, radiation, chemo, drug toxicity, cardiac surgery, or myxedema. MC in men and

what is angina pectoris

chest pain caused by inadequate flow of blood and oxygen to the heart

what is a characteristic of angina pectoris

narrowed and hardened adrenal walls

what is given to patients with angina pectoris

nitroglycerin

what is coronary thrombosis

formation of a blood clot in a coronary artery

what is myocardial infarcation

prolonged lack of blood flow which causes lack of oxygen which results in cellular death

what are 4 methods of removing a blocked artery

1) angioplasty
2) stent
3) coronary bypass
4) t-pa

what is t-pa

tissue plasminogen activator

what is angioplasty

A ballon inserted via catheter and is blownup to expand the artery to push plague against the wals and restore blood flow.

what is hypertrophy in the heart

Enlargement of the heart, occurs when it's working too hard

what happens to your maximum heart rate as you age

it decrease

_________ oxygen consumption required as you age

increased

5 things to watch as you age

1) smoking
2) high cholesterol
3) diabetes
4) chronic stress
5) hypertension (high blood pressure)